Jittery Playback and Slow Running

I have a problem in that I bought a laptop specifically to use for video editing with HitFilm Express, but I didn’t really acknowledge the fact that the graphics card was the bare minimum spec to be able to handle HitFilm. I’m now some way into the project and the software is generally running slowly, not only when trying to playback sections which I’m editing Intermittently jittery) but also when trying to move around the project workflow. Is there any way to be able to play back the edited footage smoothly without having to resort to either upgrading the graphics card or buying a new machine altogether? The spec and context of my situation is as follows: I am running an Asus N55S with an Intel Core i7 2670QM processor @ 2.2GHz, and an Nvidia Geoforce GT55M graphics card (I have just updated the driver for this). The graphics card was unable to handle the raw 1,920×1,080 HD footage at all so I have been down-scaling it all to 1,280×720.

Whilst the project is a sci-fi production, it’s not especially heavy on effects; it’s mostly a mix of basic editing, some motion tracking, a few lighting effects, masks, etc. and a couple of more sophisticated effects using some of the default CGI elements. I’ve also created a title and credit sequence with text captions and it’s been especially struggling with playing back these.

I've recently cleaned up the hard drive (not that it was in any way clogged up) and I have 150GB of free space.

I'm not so worried about slow processing per se, just that I want to be able to play back what I'm editing smoothly.

I have found this plug-in device which appears to allow smooth HD playback via an external monitor but I’m assuming my inadequate internal graphics card would still hinder playback?

Comments

The biggest cause of playback issues is footage format. What format is your footage in, and what codec does it use? Simply making sure that you are using a good editing codec like DNxHD will alleviate a lot of playback issues.

I converted the image sequence to jpg as a last resort and it has improved but still not realtime. Putting the Editor to quarter quality and 25% screen size also improves it but its no where near as smooth when you convert it to a Composite shot and use its ram preview. The ram preview in the Composite shot is really superior to the Editor proxies.

Unfortunately I’m too far down the line to re-format the video files; I would have to start again from scratch which is not something I can even contemplate. Having said that, there are two ‘episodes’ to this project so perhaps I can use a more workable codec and video format for ‘part two’.

With regards to the plug-in HD thing referred to above, would that help me in the interim in terms of playing back the timeline via an external monitor?

@chibi, what storage drive are your proxies going to? One thing about proxies--we've been told proxies are lossless, but I have never met a lossless file that could compress more than 2:1 to 3:1. Uncompressed 1280*720, 8-bit @ 24fps (i.e. Lowest resolution/bit depth/framerate you would use) is over 500Mbps/second, where 1920*1080, 16-bit @ 30fps is about 2100Mbps/second. Assuming your 1080 project is 16-bit and a 3:1 compression (unless @SimonKJones can get better data from a coder), that's a sustained data rate of close to 700Mbps, which might make your drive unhappy.

All I know is that my playback is also very jittery and slow. The preview screen works fine, and everything is good until I edit the clips on a composite screen. For example, blurry my clip for any amount of time ruins the playback.

Can you walk me through how to fix this as a beginner and if my playback is slow, will it be slow even after I export the video?

@LadyAern Generally it is best to create a thread for your issue than resurrect old threads. Old threads, even if related, will not have current information and may not be directly applicable to current versions of Hitfilm.